A project is proposed to develop and demonstrate the feasibility of an enzyme immunoassay suitable for use for personal monitoring of exposure to toxin agents. Techniques are proposed whereby it is anticipated that toxic chemicals can be bound directly from the vapor phase onto semi-dry immobilized antibodies. It is further proposed to put such immobilized antibodies into a kit that can be rapidly and conveniently developed by the user to produce a visible color if the kit (therefore, the user) is exposed to the applicable toxic agents. The specific goal of the project is to demonstrate the feasibility of this technology for detecting paraoxon, an organophosphate insecticide. Further development could then show its applicability to other toxic agents and multiple toxic agents. It is expected that this technology will have broad applications and could be used for many valuable commercial products.